1. Field of the Invention
The present invention relates to an automotive molded ceiling material which has flexibility and excellent rigidity whereby breakage is prevented during assembly operation, and to a method of producing the automotive molded ceiling material.
2. Description of the Related Art
In the car industry, there has been seen lately a tendency to produce cars the bodies of which are scaled up to accommodate them to pleasure trips, and following this, the requirement for the area of ceilings has increased from the conventional 1.5 m.sup.2 to 3.0 m.sup.2 per a car. In addition, there is an increase in car designs where openings for sunroofs or the like are provided to molded ceiling materials. Thus, the requirements for the flexural strength of molded ceiling material have risen recently to the order of 3.0 to 5.0 kg/mm.sup.2, while past requirements were 1.5 to 2.0 kg/mm.sup.2.
Corrugated board, hair felt, PS (polystyrene), glass wool, etc. have generally been used as the base materials for molded ceiling materials. However, molded ceilings using these base materials do not have strength enough for ceilings having large area or sunroofs. In attaching a molded ceiling to a car by general assembly method, the molded ceiling is inserted in the car body through its opening for rear window for reasons of assembly processes, and at the time of inserting the molded ceiling, it is sometimes bent somewhat excessively due to the narrow opening, resulting in occasional breakage of the molded ceiling for lack of sufficient strength. Further, a molded ceiling having wide area is sometimes deformed by its own weight, resulting also in breakage. In these circumstances, there is a demand for molded ceiling materials which have a rigidity satisfying higher requirements for strength and are easy to handle during assembly.
Although glass wool has been used by preference as a base material because of its nonflamability and high ability of stabilizing the shape of molded ceiling materials, it causes a problem in working environment that, for example, the glass wool scattered during molding or assembling pricks the skin. There is another problem that the molded ceiling materials produced by using glass wool delaminate in the base material layers made of the glass wool.